This invention relates to an apparatus for continuously supplying web material. In a typical use of the apparatus, the web material is fed to a web printing system which, for most efficient operation, requires an uninterrupted supply of web material to be printed. The references to web printing are provided for purposes of illustration since it will be understood that the apparatus of this invention will have application in other systems having similar requirements.
There are various systems available for providing continuous supplies of web material to a printing system or the like. These systems generally provide means for adhesively attaching a leading end portion of a new roll to the moving web of a roll which is near depletion. Such so-called "flying pasters" incorporate severing means for the roll which is near expiration, and mechanisms are then employed for moving the new roll into a running position. The old roll is removed from the apparatus, and a further roll brought into position so that the operation can be repeated.
One common flying pastor system involves two or three rolls mounted on a rotary spindle with rotation of the spindle bringing a new roll into position after a connecting and severing operation. Such systems have the disadvantage of requiring rather large amounts of space in both the horizontal and vertical directions, and they are only usable in circumstances where space is not a critical consideration.
Attempts have been made to provide efficient flying paster systems wherein rolls are moved horizontally. Such systems eliminate the need for vertical space, and Brewer U.S. Pat. No. 1,409,659 and Hoe U.S. Pat. No. 1,085,907 comprise examples of systems of this type. In these arrangements, the roll nearing depletion is moved in a horizontal direction, and a new roll moved into its place subsequent to the adhesive connecting and severing operation. A further roll then replaces the new roll so that the operation can be repeated.
Another system involves the use of rolls mounted on stationary axes. When one roll is near depletion, the flying plaster operation achieves connection with a new roll mounted on a different axis. The expired roll is then replaced by a further roll on another axis so that the operation can be repeated. Reference is made to Wood U.S. Pat. No. 1,464,463 and Phillips, et al. U.S. Pat. No. 3,252,671 for illustrations of structures of this type.